tugalo

88 FSM for the 2.5 shows power coming into the pump on the orange wire, black is ground. should be 12V.

Is it possible to reverse the electrical plug on the back of the panel? if so, that would surely screw things up......

Could be a bad relay. Try swapping around the relays on the passenger side of the engine. The fuel pump relay bypasses the ballast resistor in the start position and then switches over to put the resistor in the circuit once the engine is running. If you have jumped the resistor, then the relay is the only thing left in the circuit, other than the wiring.

Got it......it turned out to be a bent pin in the connector under the spare tire and an intermittent contact in the fuse box. looked like the previous owner jammed a wire in beside the fuse to pick up power and spread the contacts enought that they no longer grip the fuse. Chasing two problems at once with one of them intermittent is no fun...... Thanks for the help.

Hi guys, My brother has been bitten by the "no brake light bug". 87 MJ 4x4. the schematics available on-line do not match his truck. and I'm confused. We have brake lights on the drivers side, but not the passenger side. the power feed for the drivers side is a gray wire with black tracer; for the passenger side, its a brown wire. No power on the brown wire at the conncector under the spare tire. Where is the next connector in this line? Also, does the output from the brake switch go straight to the sockets in back or does it go to the emergency flasher? any help or suggestions would be great !!!!

XJ gauges and cable will fit nicely........

has anyone put a Dakota 8.25 rear axle into an MJ? If so, what is required?

run the local junkyards and check the carpets in all the Cherokees, you should find one that will clean up like new at a fraction of the cost.....

If you can find a mid-90's, mid-sized Mopar in the junkyards around you, they have a real radiator cap on the bottle and work really well. all you have to do is remove the OEM bottle and the bracket that it is mounted on, drill two holes in the firewall shelf and bolt in the new bottle. It is a different shape but it fits right in.....

My 88 does exactly the same thing, misses/skips badly at around 1800-2000 RPM with no load on the engine. Give it a little gas and it smooths right out.... I cleaned all the grounds, added some extra heavy-duty grounds and swapped in various sensors. the only thing that seemed to help it was the grounds and the Manifold Air Temp sensor. its better now but not perfect.

Remove the clock and check the small instrument panel bulb mounted on the back side. I think it is a #74. thats the usual problem

Disconnect the battery, remove the two wires from the starter. Remove the two bolts holding the starter to the engine. Its a pretty good idea to replace one of the bolts with a piece of all-thread rod and then use a nut. the two bolts are two different sizes. I'm retired Navy over in Westminster with 3 MJ's if you need parts.

My 88 stumbled badly around 1800RPM under light load. Ended up changing the coolant temp sensor and the Manifold air temp sensor. I also removed and cleaned ALL grounds, added a ground cable from the neg side of the battery to the front clip, and replaced the ground strap with a HEAVY battery cable from wally world. works good......

My son-in-law just bought his first MJ....87 short bed, 4.0 4x4 5 speed. I'm assuming that it is an AX-5. Problem is, the linkage from the 4 wheel drive lever to the transfer case is missing, so no 4 wheel drive. Can anyone send me a photo of this linkage so we can make one?

If you had the speedo cable out or just disconnected at the cluster, its quite possible that you have knocked loose one or both of the big connectors on the back of the cluster

I PM'ed and emailed you and got no reply. I am interested in the black wheel center caps.

Ditto on adding an additional separate chassis ground

Try adding an extra ground between the neg post of the battery and the front clip sheetmetal....also remove and clean all other grounds.

Go to the NAXJA forum: http://www.naxja.org/forum/index.php : and do a search on fuel pump relay. Remember, Jeep Comanche trucks and Jeep Cherokees are practically identical from the back of the front seats to the front bumper.....if it applies to a Cherokee, its a good bet that it will also apply to your Comanche. Also poke around in the NAXJA site and you will find links to complete factory maintenance manuals and wiring diagrams.

If the truck will stay running with the key held to the start position but stalls when you release the key back to the run position then this is the exact problem that lead me to find this site. If this is the case, it is a wire next to the fusible link next to the battery. I am not sure exactly which wire it is because I eventually brought it to an auto electrical shop and had them find the wire; after finding someone else who had the problem and told me how to fix it. Jim is correct with the above statement, if the relay is good, then the problem is an open circuit in the orange wire that provides power from the relay to the fuel pump when the switch is released to the run position. It is more common for the problem to be in a moving part (the relay) than a piece of wire.

The fuel pump relay is what switches the ballast resistor into the circuit. If it is bad, the jeep will start and run as long as you hold the switch in the start position. If the relay is bad, when you release the switch to the "run" position, the jeep will stall out, even if the ballast resistor is good. Swap around a couple of relays at the relay center and try it.....could just be corrosion on the plug-in contacts...

Simple check.....pull out the fuel pump relay and swap it with another one. If it works, one side of the relay is bad.......powering up the pump when in the start position, but not in the run position....

Simple check.....pull out the fuel pump relay and swap it with another one. If it works, one side of the relay is bad.......powering up the pump when in the start position, but not in the run position....

Hmmmm......how about the relay that switches the ballast resistor into and out of the circuit....

Hmmmm......how about the relay that switches the ballast resistor into and out of the circuit....